Surgical stapling device with laminated drive member

ABSTRACT

A surgical stapling device includes an elongate body, a tool assembly pivotably coupled to the elongate body for articulation, and a drive assembly. The drive assembly is movable in relation to the tool assembly to eject staples from the tool assembly and cut tissue clamped between jaws of the tool assembly. The drive assembly includes a working end that is coupled to a flexible drive beam. The flexible drive beam includes a metallic core member and outer laminates secured to opposite sides of the core member. The outer laminates are formed of a material having a lower coefficient of friction than the core member to minimize firing forces of the surgical stapling device.

FIELD

This disclosure is generally related to a surgical stapling device witha drive assembly including a flexible drive beam and, more particularly,to a surgical stapling device including an articulating tool assemblyand a drive assembly having a flexible drive beam.

BACKGROUND

Endoscopic stapling devices that include an elongate body, and a toolassembly supported on the elongate body are well known. Typically, thetool assembly is coupled to a distal portion of the elongate body by apivot member that defines a pivot axis that is transverse to alongitudinal axis of the elongate body such that the tool assembly canpivot between articulated and non-articulated positions. Such staplingdevices include a drive assembly having a flexible drive beam that canbend about the pivot axis when the tool assembly is fired to ejectstaples from the tool assembly.

To gain better access to tissue within a body cavity during anendoscopic surgical procedure, articulation of the tool assembly over arange of ninety-degrees is desirable. However, firing the staplingdevice with the tool assembly articulated to such high degrees greatlyincreases the firing forces required to fire the stapling device.

A continuing need exists in the art for a stapling device that canminimize the firing forces required to fire the stapling device when thetool assembly of the stapling device is in an articulated position.

SUMMARY

This disclosure generally relates to a surgical stapling device thatincludes an elongate body, a tool assembly pivotably coupled to theelongate body for articulation, and a drive assembly. The drive assemblyincludes a working end that is coupled to a flexible drive beam. Theflexible drive beam has a metallic core member and outer laminatessecured to opposite sides of the core member. The outer laminates areformed of a material having a lower coefficient of friction than thecore member to minimize firing forces of the surgical stapling device.

Aspects of the disclosure are directed to a drive assembly including aworking end and a drive beam assembly. The working end has an I-beamconfiguration and includes a first beam, a second beam, and a verticalstrut interconnecting the first beam to the second beam. The drive beamassembly includes a core member and outer laminates. The core memberincludes a flexible beam having planar side walls, a top wall, and abottom wall. The flexible beam has a distal portion that is secured tothe working end and the outer laminates are supported along the planarside walls of the flexible beam. The core member is formed from a metaland the outer laminates are formed from a material having a lowercoefficient of friction than the core member.

Other aspects of the disclosure are directed to a stapling deviceincluding an adapter assembly, a tool assembly, and a drive assembly.The adapter assembly defines a longitudinal axis and has a proximalportion and a distal portion. The tool assembly is supported on thedistal portion of the adapter assembly by a pivot member that defines apivot axis that is transverse to the longitudinal axis such that thetool assembly can articulate between a non-articulated position andarticulated positions about the pivot axis. The tool assembly includesan anvil assembly and a cartridge assembly that are movable in relationto each other between open and clamped positions. The drive assembly ismovable in relation to the tool assembly between retracted and advancedpositions to actuate the tool assembly and includes a working end and adrive beam assembly. The working end has an I-beam configuration andincludes a first beam, a second beam, and a vertical strutinterconnecting the first beam to the second beam. The drive beamassembly includes a core member and outer laminates. The core memberincludes a flexible beam having planar side walls, a top wall, and abottom wall. The flexible beam has a distal portion secured to theworking end, and the outer laminates are supported along the planar sidewalls of the flexible beam. The core member is formed from a metal andthe outer laminates are formed from a material having a lowercoefficient of friction than the core member.

In aspects of the disclosure, the outer laminates are formed frompolytetrafluoroethylene.

In some aspects of the disclosure, the core member is formed fromstainless steel.

In certain aspects of the disclosure, the outer laminates are coupledtogether by a top wall to form a U-shaped laminate assembly that definesa cavity and an opening opposite the top wall.

In aspects of the disclosure, the cavity receives the core memberthrough the opening.

In some aspects of the disclosure, the bottom wall of the core memberdefines notches and one of the outer laminates includes fingers that arealigned with the notches and extend into the opening.

In certain aspects of the disclosure, the fingers are received withinthe notches in snap-fit fashion when the U-shaped laminate assembly ispositioned on the core member to secure the U-shaped laminate assemblyon the core member.

In some aspects of the disclosure, the core member defines openings, andeach of the outer laminates defines openings that are aligned with theopenings in the core member.

In certain aspects of the disclosure, the openings in the outerlaminates are bounded by inwardly projecting ribs that are receivedwithin the openings in the core member, and the inwardly extending ribson the outer laminates are secured together within the openings of thecore member to secure the outer laminates to opposite sides of the coremember.

In aspects of the disclosure, the outer laminates are coupled togetherwith top and bottom walls to form a rectangular laminate assembly thatdefines a cavity that receives the core member.

In some aspects of the disclosure, each of the top and bottom walls ofthe core member includes a protrusion and each of the top and bottomwalls of the rectangular laminate assembly defines a cutout thatreceives one of the protrusions to secure the rectangular laminateassembly on the core member.

In certain aspects of the disclosure, each of the outer laminatesincludes a distal extension that defines a cutout, and the working endof the drive assembly includes protrusions that are received within thecutouts to secure the rectangular laminate assembly to the core member.

In aspects of the disclosure, the outer laminates and the core memberdefine openings and the rectangular laminate assembly is secured to thecore member with fasteners selected from the group consisting of pins,dowels, rivets, and grommets, that extend through the openings.

In some aspects of the disclosure, each of the outer laminates definesan opening and includes a protrusion, and the core member includeselongate slots that receive the protrusions of the outer laminates.

In certain aspects of the disclosure, the protrusion of each of theouter laminates is received within the opening of the other of the outerlaminates to secure the outer laminates to each other and to the coremember.

In aspects of the disclosure, the elongate slots in the core memberfacilitate relative movement between the outer laminates and the coremember.

Other aspects, features, and advantages will be apparent from thedescription, the drawings, and the claims that follow.

BRIEF DESCRIPTION OF DRAWINGS

Various aspects and features of the disclosure are described withreference to the drawings wherein like numerals designate identical orcorresponding elements in each of the several views wherein:

FIG. 1 is a side perspective view from a distal end of a surgicalstapling device according to aspects of the disclosure with a toolassembly of the stapling device in a clamped and non-articulatedposition and the tool assembly shown in phantom in the clamped andarticulated positions;

FIG. 2 is a side perspective view of a reload assembly of the surgicalstapling device shown in FIG. 1 with the tool assembly in anon-articulated, open position;

FIG. 3 is a side perspective partially exploded view of the reloadassembly shown in FIG. 2 with the tool assembly shown in the openposition;

FIG. 4 is a side perspective exploded view of a drive assembly of thestapling device shown in FIG. 3;

FIG. 5 is a cross-sectional view taken along section line 5-5 of FIG. 4;

FIG. 6 is an enlarged view of the indicated area of detail shown in FIG.3;

FIG. 7 is a cross-sectional view taken through a drive beam and outerlaminates of the drive assembly shown in FIG. 6 as the outer laminatesare positioned onto the drive beam;

FIG. 8 is a cross-sectional view through the drive assembly taken alongsection line 8-8 of FIG. 6;

FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 8;

FIG. 10 is a top view of the tool assembly of the stapling device shownin FIG. 1 with the tool assembly in the clamped position and the driveassembly in a partially retracted position;

FIG. 11 is a top view of the tool assembly of the stapling device shownin FIG. 1 with the tool assembly in the clamped position and the driveassembly in an advanced position;

FIG. 12 is a side perspective view of an alternate version of the driveassembly of the surgical stapling device shown in FIG. 1;

FIG. 13 is a cross-sectional view taken through the drive assembly alongsection line 13-13 of FIG. 12;

FIG. 14 is an exploded view of the drive assembly shown in FIG. 12;

FIG. 15 is a side perspective view of a distal portion of anotheralternate version of the drive assembly of the surgical stapling deviceshown in FIG. 1;

FIG. 16 is a side view of the distal portion of the drive assembly shownin FIG. 15 with parts separated;

FIG. 17 is a cross-sectional view taken through the drive assembly alongsection line 17-17 of FIG. 15 as the outer laminates are positioned ontothe drive beam;

FIG. 18 is a cross-sectional view taken through the drive assembly alongsection line 18-18 of FIG. 15 with the outer laminates secured to thedrive beam;

FIG. 19 is a side perspective view of a distal portion of yet anotheralternate version of the drive assembly of the surgical stapling deviceshown in FIG. 1;

FIG. 20 is a side view of the distal portion of the drive assembly shownin FIG. 19 with parts separated;

FIG. 21 is a side perspective view with parts separated of anotheralternate version of the drive assembly of the surgical stapling deviceshown in FIG. 1;

FIG. 22 is a side perspective view with parts separated of anotheralternate version of the drive assembly of the surgical stapling deviceshown in FIG. 1;

FIG. 23 is a side perspective view of a distal portion of the driveassembly shown in FIG. 22 assembled;

FIG. 24 is a cross-sectional view taken along section line 24-24 of FIG.23;

FIG. 25 is a cross-sectional view of a portion of another alternateversion of the drive assembly of the surgical stapling device shown inFIG. 1; and

FIG. 26 is a cross-sectional view of a portion of yet another alternateversion of the drive assembly of the surgical stapling device shown inFIG. 1.

DETAILED DESCRIPTION

The disclosed surgical stapling device will now be described in detailwith reference to the drawings in which like reference numeralsdesignate identical or corresponding elements in each of the severalviews. However, it is to be understood that aspects of the disclosureincluded herein are merely exemplary of the disclosure and may beembodied in various forms. Well-known functions or constructions are notdescribed in detail to avoid obscuring the disclosure in unnecessarydetail. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the disclosure in virtually any appropriatelydetailed structure. In addition, directional terms such as front, rear,upper, lower, top, bottom, and similar terms are used to assist inunderstanding the description and are not intended to limit thedisclosure.

In this description, the term “proximal” is used generally to refer tothat portion of the device that is closer to a clinician during use ofthe device for its intended purpose, while the term “distal” is usedgenerally to refer to that portion of the device that is farther fromthe clinician during use of the device for its intended purpose. Inaddition, the terms “about” and “substantially” are intended to includea range that includes the listed parameter and plus or minus ten percentof the listed parameter. Further, the term “clinician” is used generallyto refer to medical personnel including doctors, nurses, and supportpersonnel.

This disclosure is directed to a surgical stapling device that includesan elongate body, a tool assembly, and a drive assembly. The driveassembly is movable in relation to the tool assembly to eject staplesfrom the tool assembly and cut tissue clamped between jaws of the toolassembly. The tool assembly is secured to the elongate body by a pivotmember that defines a pivot axis that is transverse to a longitudinalaxis of the elongate body such that the tool assembly can articulateabout the pivot axis between a non-articulated position and articulatedpositions. The drive assembly includes a working end that is coupled toa flexible drive beam. The flexible drive beam includes a metallic coremember and outer laminates that are formed of a material having a lowercoefficient of friction than the core member and are secured about thecore to minimize firing forces of the surgical stapling device.

FIG. 1 illustrates a surgical stapling device shown generally asstapling device 10 that includes a handle assembly 12, an elongate bodyor adapter assembly 14, and a tool assembly 16. In aspects of thedisclosure, the handle assembly 12 is powered and includes a stationaryhandgrip 18 and actuation buttons 20. The actuation buttons 20 areoperable to actuate various functions of the tool assembly 16 via theadapter assembly 14 including approximation, stapling, and cutting oftissue. Although not shown, the handle assembly 16 can support batteries(not shown) that provide energy to the handle assembly 12 to actuate thestapling device 10. Although the stapling device 10 is illustrated as apowered stapling device, it is envisioned that the advantages of thisdisclosure are suitable for use with manually powered surgical staplingdevices as well as robotically controlled stapling devices.

In aspects of the disclosure, the tool assembly 16 forms part of areload assembly 22 that includes the tool assembly 16 and a body portion24. The body portion 24 has a proximal portion that is releasablycoupled to the adapter assembly 14 (FIG. 1) of the stapling device 10and a distal portion that supports the tool assembly 16. It isenvisioned that the tool assembly 16 need not form part of a reloadassembly 22 but can be fixedly connected to a distal portion of theadapter assembly 14.

FIGS. 2 and 3 illustrate the reload assembly 22 with the tool assembly16 supported on the distal portion of the body portion 24 by a pivotmember 26 and coupling members 28. The pivot member 26 is supported on amounting member 30 that is secured to a proximal portion of the toolassembly 16 and defines a pivot axis “Z” (FIG. 1) that is transverse toa longitudinal axis “X” (FIG. 1) of the body portion 24 of the reloadassembly 24 of the adapter assembly 14. Each of the coupling members 28have a distal portion that is coupled to the pivot member 26 and aproximal portion that is fixedly secured to the body portion 24 of thereload assembly 22 such that the tool assembly 16 can pivot about thepivot axis “Z”.

The tool assembly 16 includes an anvil assembly 32 and a cartridgeassembly 34. The anvil assembly 32 includes an anvil plate 36 thatdefines staple forming pockets 38 (FIG. 2) and a central knife slot 40.The staple forming pockets 38 are aligned in rows on opposite sides ofthe central knife slot 40 and receive staples (not shown) that areejected from the cartridge assembly 34 when the stapling device 10 isfired to form the staples in tissue clamped between the anvil andcartridge assemblies 32 and 34.

The cartridge assembly 34 includes a channel member 42 and a staplecartridge 44 that is supported within the channel member 42. The staplecartridge 44 defines staple slots 46 (FIG. 3) and a central knife slot48. The staple slots 46 are aligned in rows on opposite sides of thecentral knife slot 48 and receive staples (not shown). The channelmember 42 also defines a central knife slot 48 a that is axially alignedwith the knife slot 48 in the staple cartridge 44. In aspects of thedisclosure, the anvil assembly 32 is fixedly secured to the mountingmember 30 and the cartridge assembly 34 is pivotably supported on themounting member 30 such that the cartridge assembly 34 is movable inrelation to the anvil assembly 32 between open and clamped positions. Inthe clamped position, the anvil plate 36 of the anvil assembly 32 is injuxtaposed alignment with the staple cartridge 44 of the cartridgeassembly 34. It is envisioned that the anvil assembly 32 could bepivotably secured to the mounting member 30 and the cartridge assembly34 could be fixedly secured to the mounting member 30. U.S. Pat. No.7,891,534 (“the '534 Patent”) discloses a tool assembly in detailsuitable for use with the stapling device 10.

The body portion 24 of the reload assembly 22 includes a body 50, adrive assembly 52, and an outer tube 54. In aspects of the disclosure,the body 50 is formed of body half-sections 50 a and 50 b that, whensecured together, form a longitudinal channel 56 that receives the driveassembly 52 to facilitate movement of the drive assembly 52 betweenretracted and advanced positions within the body 50. The body 50 isreceived within the outer tube 54 when the body half-sections 50 a and50 b are assembled.

FIGS. 4-9 illustrate the drive assembly 52 which includes a working end60 and a flexible drive beam assembly 62. The working end 60 of thedrive assembly 52 has an I-beam configuration and includes a first beam64, a second beam 66, and a vertical strut 68 that fixedly couples thefirst beam 64 to the second beam 66. In aspects of the disclosure, thevertical strut 68 supports or includes a distally facing cutting edge71. The working end 60 of the drive assembly 52 is received within andmovable through the tool assembly 16 to move the tool assembly 16between the open and clamped positions and to fire staples from thestaple cartridge 44. For a more detailed description of the interactionof the working end 60 of the drive assembly 52 and the tool assembly 16,see the '534 Patent.

The drive beam assembly 62 includes a metallic core member 70 and outerlaminates 72 that are positioned on opposite sides of the core member70. The core member 70 includes a flexible beam 74 having planar sidewalls 76, a top wall 78, and a bottom wall 80, a proximal portion, and adistal portion. The distal portion of the flexible beam 74 is coupled tothe working end 60 of the drive assembly 60. In aspects of thedisclosure, the distal portion of the core member 70 is secured to theworking end 60 of the drive assembly 60 by welding. Alternately, othertechniques can be used to secure the working end 60 of the driveassembly 52 to the flexible beam 74 such as interlocking structure,e.g., dovetail connectors. In aspects of the disclosure, the core member70 can be formed of stainless steel, e.g., stainless steel 301, althoughit is envisioned that other metals can be used to form the core member70. It is also envisioned that the core member 70 can be formed fromstacked sheets of metal.

The outer laminates 72 of the drive beam assembly 62 are secured to theside walls 76 of the core member 70. In aspects of the disclosure, theouter laminates 72 are formed of a flexible material that has a lowercoefficient of friction than the core member 70. In some aspects of thedisclosure, the outer laminates 72 are formed frompolytetrafluoroethylene (PTFE) although the use of other materials toform the outer laminates 72 is also envisioned such as nylons andpolypropylene. It is envisioned that the material selected to form theouter laminates reduces the coefficient of friction between the drivebeam assembly 62 and the metal components of the tool assembly 16 tobetween about 0.05 and 0.2.

In aspects of the disclosure, the outer laminates 72 are coupledtogether by a top wall 82 to form a U-shaped laminate assembly 83 thatdefines a cavity 84 with the outer laminates 72. The cavity 84 isdimensioned to receive the core member 70. The U-shaped laminateassembly 83 defines an opening 86 (FIG. 4) that is positioned oppositeto the top wall 82 that allows passage of the laminate assembly 83 aboutthe core member 70 such that the outer laminates 72 are positioned alongthe side walls 76 of the core member 70.

In aspects of the disclosure, the bottom wall 80 of the core member 70defines notches 88 and one of the outer laminates 72 includes fingers 90that extend across the opening 86 (FIG. 5) of the laminate assembly 83.The fingers 90 are positioned to be received within the notches 88 ofthe core member 70. When the U-shaped laminate assembly 83 is slid ontothe core member 70 in the direction indicated by arrows “A” in FIGS. 4and 7, the fingers 90 engage one of the side walls 76 of the core member70 to deform the outer laminate 72 supporting the fingers 90 outwardlyin the direction of arrow “B”. When the fingers 90 are moved intoalignment with the notches 88 in the core member 70, the outer laminate72 supporting the fingers 90 snaps inwardly in the direction indicatedby arrow “C” in FIG. 8 to position the fingers 90 within the notches 88and secure the U-shaped laminate assembly 83 about the core member 70.

FIG. 10 illustrates the tool assembly 16 articulated ninety-degrees withthe drive assembly 52 in a partially advanced or clamping position tomove the tool assembly 16 to the clamped position. For a detaileddescription of the interaction between the drive assembly 52 and thetool assembly 16, see the '534 Patent. In this position, the drive beamassembly 62 is bent ninety-degrees at a position adjacent the pivotmember 26.

FIG. 11 illustrates the drive assembly 52 advanced to fire or actuatethe tool assembly 16. When the drive assembly 52 is advanced to fire thestapling device 10 with the tool assembly in an articulated position,the drive beam assembly 62 is advanced along a ninety-degree bend in thedirection of arrows “D” to advance the working end 60 of the driveassembly 52 through the tool assembly 16. Advancement of the working end60 through the tool assembly 16 advances an actuation sled through thetool assembly 16 to eject staples from the staple cartridge 44 and cuttissue clamped between the anvil assembly 32 and the cartridge assembly34. By providing outer laminates 72 on each side 76 of the core member70, the frictional forces on the drive assembly 52 are substantiallyreduced to lower the forces required to fire the stapling device 10(FIG. 1).

FIGS. 12-14 illustrate an alternative version of the drive assembly 52of the stapling device 10 shown generally as drive assembly 152. Thedrive assembly 152 includes a working end 160 and a flexible drive beamassembly 162. The working end 160 of the drive assembly 152 is identicalto the working end 60 (FIG. 4) of the drive assembly 52 and will not bedescribed in further detail herein. The flexible drive beam assembly 162includes a core member 170 and outer laminates 172. The core member 170defines elongated openings 174 that extend between side walls 176 of thecore member 170 through the core member 170. Each of the outer laminates172 defines elongated openings 178 that are aligned with the elongatedopenings 174 in the core member 170 and extend through the outerlaminate 172. Each of the elongated openings 178 is bounded by aninwardly projecting rib 180 that is received within a respective one ofthe openings 174 in the core member 170 to secure the outer laminates172 to the side walls 176 of the core member 170. In aspects of thedisclosure, the ribs 180 of the outer laminates 172 can be securedtogether such as by ultrasonic welding to secure the outer laminates 172to the opposite sides 176 of the core member 170.

The core member 170 and the outer laminates 172 in this version of thedrive assembly and versions of the drive assembly described below areformed of the materials identified above regarding core member 70 andouter laminates 72 and will not be described in further detail herein.

FIGS. 15-18 illustrate an alternative version of the drive assembly 52(FIG. 4) of the stapling device 10 shown generally as drive assembly252. The drive assembly 252 includes a working end 260 and a flexibledrive beam assembly 262. The working end 260 of the drive assembly 252is identical to the working end 60 (FIG. 4) of the drive assembly 52 andwill not be described in further detail herein. The flexible drive beamassembly 262 includes a core member 270 and outer laminates 272 that arecoupled together by top and bottom walls 282 to form a rectangularlaminate assembly 283 that defines a cavity 286. The cavity 286 isdimensioned to slidably receive the core member 270. In aspects of thedisclosure, top and bottom walls 278 and 280 of the core member 270include protrusions 288 that include a proximally facing ramped surfaceand a distal stop surface that is perpendicular to a longitudinal axisof the core member 270. The rectangular laminate assembly 283 includes adistal portion having cutouts 290 in top and bottom walls 282 a and 282b of the laminate assembly 283. When the core member 270 is receivedwithin the cavity 286 and the laminate assembly 283 is slid in thedirection of arrows “E” in FIG. 16, the protrusions 288 are received inthe cutouts 290 to secure the laminate assembly 283 to about the coremember 270.

In aspects of the disclosure, the distal portion of the laminateassembly 283 includes slots 292 (FIG. 15) that provide flexibility tothe distal portion of the laminate assembly 283 to allow the top andbottom walls 282 of the laminate assembly 283 to flex outwardly in thedirection of arrows “F” in FIG. 17 to allow the protrusions 288 on thecore member 270 to pass into the cutouts 290 in the laminate assembly283. Once the protrusions 288 pass into the cutouts 290, the distalportion of the laminate assembly 283 returns to its unbiased position tosecure the laminate assembly 283 to the core member 270.

FIGS. 19 and 20 illustrate an alternative version of the drive assembly252 (FIG. 15) of the stapling device 10 shown generally as driveassembly 352. The drive assembly 352 is substantially similar to thedrive assembly 252 except that the cutouts 390 in the rectangularlaminate assembly 383 are formed on a distal extension 372 a of theouter laminates 372 rather than on the top and bottom walls of thelaminate assembly, and the protrusions 388 are formed on the verticalstrut 368 of the working end 360 of the drive assembly 352 rather thanon top and bottom walls of the core member. When the laminate assembly383 is slid onto the core member 370 in the direction of arrows “G” inFIG. 20, the protrusions 388 on the vertical strut 368 of the workingend 360 of the drive assembly 352 are received within the cutouts 390formed in the distal extensions of the outer laminates 372 in the samemanner protrusions 288 (FIG. 18) are received in the cutouts 290, tosecure the laminate assembly 383 to the core member 370.

FIG. 21 illustrates another alternative version of the drive assembly 52of the stapling device 10 shown generally as drive assembly 452. Thedrive assembly 452 includes a working end 460 and a flexible drive beamassembly 462. The working end 460 of the drive assembly 452 is identicalto the working end 60 (FIG. 4) of the drive assembly 52 and will not bedescribed in further detail herein. The flexible drive beam assembly 462includes a core member 470 and outer laminates 472 that are coupledtogether by top and bottom walls 482 to form a rectangular laminateassembly 483 that defines a cavity 486. The cavity 486 receives the coremember 470. In aspects of the disclosure, the core member 470 and theouter laminates 472 define openings 492 that receive pins or dowels 494to secure core member 470 to the outer laminates 472 within the cavity486.

FIGS. 22-24 illustrate another alternative version of the drive assembly52 of the stapling device 10 shown generally as drive assembly 552. Thedrive assembly 552 includes a working end 560 and a flexible drive beamassembly 562. The working end 560 of the drive assembly 552 is identicalto the working end 60 (FIG. 4) of the drive assembly 52 and will not bedescribed in further detail herein. The flexible drive beam assembly 562includes a core member 570 and outer laminates 572. In aspects of thedisclosure, each of the outer laminates 572 defines a stepped opening574 and includes an inwardly extending protrusion 594 with an enlargedhead 596. The core member 570 defines elongated slots 598 that arealigned with the protrusions 594. The protrusions 594 are positionedthrough the elongated slots 598 in the core member 570 and pressed intothe stepped openings 574 of the other outer laminate 572 to secure theouter laminates 572 to each other and to the core member 570. Byproviding elongated slots 598 in the core member 570, the outerlaminates 572 can slide in unison in relation to the core member 570. Itis envisioned that each of the outer laminates 572 may include oneprotrusion 594 and define one opening 574, or one of the outer laminates572 can define two openings 574 and the other of the outer laminates 572can include two protrusions 594.

FIGS. 25 and 26 illustrate other alternative versions of the driveassembly 52 of the stapling device 10 shown generally as driveassemblies 652 and 752. In the drive assembly 652, the outer laminates672 and the core member 670 of the drive beam assembly 662 defineopenings 674 and 676, respectively, that are aligned with each other.The openings 674 and 676 receive a grommet 678 (FIG. 25) that securesthe outer laminates 672 to the core member 670. In this aspect of thedisclosure, the grommet 678 includes outer ends 680 that diverge andengage angled surfaces 682 of the outer laminates 672 that define aportion of the openings 674 to tightly secure the outer laminates 672 tothe core member 670.

The drive assembly 752 (FIG. 26) is substantially the same as the driveassembly 652 (FIG. 25) except that the outer laminates 772 are securedto each other and to the core member 770 using a tubular rivet 778. Inthis aspect of the disclosure, the openings 774 in the outer laminates772 are stepped and receive head portions 780 of the rivet 778 to securethe outer laminates 772 to each other and to the core member 770.

Persons skilled in the art will understand that the devices and methodsspecifically described herein and illustrated in the accompanyingdrawings are non-limiting exemplary embodiments. It is envisioned thatthe elements and features illustrated or described in connection withone exemplary embodiment may be combined with the elements and featuresof another without departing from the scope of the disclosure. As well,one skilled in the art will appreciate further features and advantagesof the disclosure based on the above-described embodiments. Accordingly,the disclosure is not to be limited by what has been particularly shownand described, except as indicated by the appended claims.

What is claimed is:
 1. A drive assembly comprising: a working end having an I-beam configuration including a first beam, a second beam, and a vertical strut interconnecting the first beam to the second beam; and a drive beam assembly including a core member and outer laminates, the core member including a flexible beam having planar side walls, a top wall, and a bottom wall, the flexible beam having a distal portion secured to the working end, the outer laminates supported along the planar side walls of the flexible beam, wherein the core member is formed from a metal and the outer laminates are formed from a material having a lower coefficient of friction than the core member.
 2. The drive assembly of claim 1, wherein the outer laminates are formed from polytetrafluoroethylene.
 3. The drive assembly of claim 2, wherein the core member is formed from stainless steel.
 4. The drive assembly of claim 1, wherein the outer laminates are coupled together by a top wall to form a U-shaped laminate assembly that defines a cavity and an opening opposite the top wall, the cavity receiving the core member through the opening.
 5. The drive assembly of claim 4, wherein the bottom wall of the core member defines notches and one of the outer laminates includes fingers that are aligned with the notches and extend into the opening, the fingers received within the notches in snap-fit fashion when the U-shaped laminate assembly is positioned on the core member to secure the U-shaped laminate assembly on the core member.
 6. The drive assembly of claim 1, wherein the core member defines openings, and each of the outer laminates defines openings that are aligned with the openings in the core member, the openings in the outer laminates being bounded by inwardly projecting ribs that are received within the openings in the core member, the inwardly extending ribs on the outer laminates being secured together within the openings of the core member to secure the outer laminates to opposite sides of the core member.
 7. The drive assembly of claim 1, wherein the outer laminates are coupled together with top and bottom walls to form a rectangular laminate assembly, the rectangular laminate assembly defining a cavity that receives the core member.
 8. The drive assembly of claim 7, wherein each of the top and bottom walls of the core member includes a protrusion and each of the top and bottom walls of the rectangular laminate assembly defines a cutout that receives one of the protrusions to secure the rectangular laminate assembly on the core member.
 9. The drive assembly of claim 7, wherein each of the outer laminates includes a distal extension that defines a cutout, and the working end of the drive assembly includes protrusions, the protrusions received within the cutouts to secure the rectangular laminate assembly to the core member.
 10. The drive assembly of claim 7, wherein the outer laminates and the core member define openings and the rectangular laminate assembly is secured to the core member with fasteners selected from the group consisting of pins, dowels, rivets, and grommets, the fasteners extending through the openings.
 11. The drive assembly of claim 1, wherein each of the outer laminates defines an opening and includes a protrusion, and the core member includes elongate slots that receive the protrusions of the outer laminates, the protrusion of each of the outer laminates received within the opening of the other of the outer laminates to secure the outer laminates to each other and to the core member, the elongate slots in the core member facilitating relative movement between the outer laminates and the core member.
 12. A stapling device comprising: an adapter assembly defining a longitudinal axis and having a proximal portion and a distal portion; a tool assembly supported on the distal portion of the adapter assembly by a pivot member that defines a pivot axis that is transverse to the longitudinal axis such that the tool assembly can articulate between a non-articulated position and articulated positions about the pivot axis, the tool assembly including an anvil assembly and a cartridge assembly that are movable in relation to each other between open and clamped positions; and a drive assembly movable in relation to the tool assembly between retracted and advanced positions to actuate the tool assembly, the drive assembly including: a working end having an I-beam configuration including a first beam, a second beam, and a vertical strut interconnecting the first beam to the second beam; and a drive beam assembly including a core member and outer laminates, the core member including a flexible beam having planar side walls, a top wall, and a bottom wall, the flexible beam having a distal portion secured to the working end, the outer laminates supported along the planar side walls of the flexible beam, wherein the core member is formed from a metal and the outer laminates are formed from a material having a lower coefficient of friction than the core member.
 13. The stapling device of claim 12, wherein the outer laminates are formed from polytetrafluoroethylene.
 14. The stapling device of claim 13, wherein the core member is formed from stainless steel.
 15. The stapling device of claim 12, wherein the outer laminates are coupled together by a top wall to form a U-shaped laminate assembly that defines a cavity and an opening opposite the top wall, the cavity receiving the core member through the opening.
 16. The stapling device of claim 15, wherein the bottom wall of the core member defines notches and one of the outer laminates includes fingers that are aligned with the notches and extend into the opening, the fingers received within the notches in snap-fit fashion when the U-shaped laminate assembly is positioned on the core member to secure the U-shaped laminate assembly on the core member.
 17. The stapling device of claim 12, wherein the core member defines openings, and each of the outer laminates defines openings that are aligned with the openings in the core member, the openings in the outer laminates being bounded by inwardly projecting ribs that are received within the openings in the core member, the inwardly extending ribs on the outer laminates being secured together within the openings of the core member to secure the outer laminates to opposite sides of the core member.
 18. The stapling device of claim 12, wherein the outer laminates are coupled together with top and bottom walls to form a rectangular laminate assembly, the rectangular laminate assembly defining a cavity that receives the core member.
 19. The stapling device of claim 18, wherein each of the top and bottom walls of the core member includes a protrusion and each of the top and bottom walls of the rectangular laminate assembly defines a cutout that receives one of the protrusions to secure the rectangular laminate assembly on the core member.
 20. The stapling device of claim 18, wherein each of the outer laminates includes a distal extension that defines a cutout, and the working end of the drive assembly includes protrusions, the protrusions received within the cutouts to secure the rectangular laminate assembly to the core member. 